Intensive investigations on meiofauna of marine sediments of the seas around the world have made a remarkable contribution to systematic zoology during the twentieth century with discovery of many aberrant taxa new to science. The fauna comprising almost all the free-living groups of invertebrate animals from Ciliophora to Tunicata are highly modified to answer biological demands of this turbulent environment. Accordingly, diverse groups of animals showed similar structural modifications, presenting an excellent example of ecological convergence in evolution. Thus, the fauna exhibits astonishing morphological diversity, but there is yet no consolidated publication on it. In the circumstances, the author prepared a comprehensive and concise work dealing with meiofauna comprising about 32 groups, 340 families, 1260 genera and 2220 species, a first of its kind in the history of marine zoology. As a picture is worth a thousand words, available full figures of all the species are given with a brief description of diagnostic features to help their identification. It is earnestly hoped that this work would be quite useful in understanding the basic diversity of meiofauna at a glance and inspire further research in this field. As such, the book definitely deserves a place on the library shelf of all national and international marine zoological institutions of higher learning interested in the study of these strange creatures.